Observations

Description

Valves are half-lanceolate or half-elliptical, with the keel of the raphe positioned along the straight margin, rather than along the curved convex margin. The frustule has hantzschioid symmetry. Fibulae number 8-12 in 10 µm. Striae are visible, but are not punctate.

The genus was described from African material and is based on Cymbellonitzschia minima Hustedt, a taxon which has its keel located along the arched portion of the valve, and was described for a species in Africa. Cymbellonitzschia diluviana is present in late glacial sediments and rarely in Recent lake collections in Europe (Jewson and Lowry 1993). It is difficult to imagine the symmetry and raphe organization of the African species and the northern latitude species are part of the same monophyletic group.

In the US, this species is known from large, cool, clean water lakes and is often associated with psammic habitats.

Original Images

Cite This Page: Kociolek, P. (2011). Cymbellonitzschia diluviana. In Diatoms of the United States. Retrieved March 31, 2015, from http://westerndiatoms.colorado.edu/taxa/species/cymbellonitzschia_diluviana

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

North American Diatom Ecological Database (NADED)

Autecology Discussion

Habits

Size Range

101-1000 µm3 (ie Amphora veneta)

Motility

moderately motile (e.g. Navicula tripunctata)

Attachment

prostrate (e.g. mucilage pad)

Habitat

benthic

Colony

solitary

EMAP Assessment

The Environmental Protection Agency (EPA) western Environmental Monitoring and Assessment Program (EMAP) study was completed during the years 2000-2004 (see citations at bottom of this page). Over 1200 streams and rivers in 12 western states (Arizona, California, Colorado, Idaho, Montana, Nevada, North Dakota, Oregon, South Dakota, Utah, Washington and Wyoming) were selected for sampling based on a stratified randomized design. This type of design insures that ecological resources are sampled in proportion to their actual geographical presence. Stratified randomized design also allows for estimates of stream length with a known confidence in several “condition classes” (good or least-disturbed, intermediately-disturbed, and poor or most-disturbed) for biotic condition, chemistry and habitat.

EMAP Distribution

Cymbellonitzschia diluviana

Distribution

The distribution map represents the relative abundance of this Cymbellonitzschia diluviana in the western EMAP study. Relative abundance is a measure of the proportion of cells of this species based on a "fixed count" of 300 total diatom cells counted and identified. Each of the western EMAP sample sites is shown, either with a black dot for sites where Cymbellonitzschia diluviana was not recorded, or with a red circle indicating the relative abundance of Cymbellonitzschia diluviana.

Note that the size of the proportional symbols varies between species to help show both abundant and rare species.

Scale for the map to the left

EMAP Response Plots

Cymbellonitzschia diluviana

Responses

The 15 response plots show an environmental variable (x axis) against the relative abundance (y axis) of Cymbellonitzschia diluviana from all the stream reaches where it was present. Note that the relative abundance scale is the same on each plot. Explanation of each environmental variable and units are as follows:

ELEVATION = stream reach elevation (meters)STRAHLER = distribution plot of the Strahler Stream Order SLOPE = stream reach gradient (degrees)W1_HALL = an index that is a measure of streamside (riparian) human activity that ranges from 0 - 10, with a value of 0 indicating of minimal disturbance to a value of 10 indicating severe disturbance.PHSTVL = pH measured in a sealed syringe sample (pH units)log_COND = log concentration of specific conductivity (µS/cm)log_PTL = log concentration of total phosphorus (µg/L)log_NO3 = log concentration of nitrate (µeq/L)log_DOC = log concentration of dissolved organic carbon (mg/L)log_SIO2 = log concentration of silicon (mg/L)log_NA = log concentration of sodium (µeq/L)log_HCO3 = log concentration of the bicarbonate ion (µeq/L)EMBED = percent of the stream substrate that is embedded by sand and fine sedimentlog_TURBIDITY = log of turbidity, a measure of cloudiness of water, in nephelometric turbidity units (NTU).DISTOT = an index of total human disturbance in the watershed that ranges from 1 - 100, with a value of 0 indicating of minimal disturbance to a value of 100 indicating severe disturbance.